Magnetic random access memories (to be referred to as MRAMs hereinafter) using the magnetoresistive effects of ferromagnetic materials have recently attracted interest as next-generation solid-state nonvolatile memories capable of speeding up read/write, increasing the capacity, and implementing a low-power operation. As the read method of the MRAMs, a method of feeding a current through a memory cell and reading data based on the magnitude of the value of the current that has flowed is used in general.